Bore-in strike and means for securing same



y 1966 E. L. SCHLAGE 3,251,619

BORE-IN STRIKE AND MEANS FOR SECURING SAME Filed May 10, 1963 2 Sheets-Sheet l INVENTOR. ERNEST L. SCHLAGE A T TOP/VEV May 17, 1966 E. L. SCHLAGE 3,251,519

I BORE-IN STRIKE AND MEANS FOR SECURING SAME Filed May 10, 11963 2 Sheets-Sheet 2 INVENTOR. ERNEST L. SCHLAGE i i VF M 40M.

IOWA \l ATTORNEY United States Patent 3 BORE-IN STRIKE ANEARB IIEANS F OR SECURING This invention relates to a strike for a door lock and more particularly to a combination strike plate and strike box which is adapted to be mounted in a bore in a door jamb. The invention also provides novel fastening means for fastening a strike or similar article within a cylindrical opening.

Heretofore it has been customary to make strikes generally rectangular in shape and to sink them in a mortise in a door jamb and secure the strike plate by means of screws. It is desirable to economize on the labor involved in the installation of the strike and in the cost of manufacture. Also, it is desirable to include a strike box integral'with the strike plate so that only one element is required to be secured to the door jamb.

An attempt has heretofore been made to apply a combination strike plate and strike box to a jamb by providing bores into which the box is received. Although this technique is desirable in that it obviates the time consuming step of forming a cavity for the strike box by means of chiseling, no successful method has been evolved for securing a combination strike plate and strike box in a single bored sole.

The main object of the present invention is to provide a novel strike plate and strike box combination which has advantages both in economy of manufacture and ease of installation.

Another object of the invention is the provision of an improved fastening means to permit a secure installation of the strike plate and box combination with a door jamb which requires only the use of a boring tool and a screw driver.

Still another object of the invention is the provision of a surface mounted strike which requires no 'mortising and which may be removed from the door jamb for the purpose of replacement without mutilating said jamb.

Yet another object of the invention is the provision of an improved fastening element that may be used as an anchor within a cylindrical opening for securing a member at the outer end of said opening.

Another object of the invention is the provision of a combination strike plate and strike -box together with fastening means therefor which need not be separated from the strike plate and strike box during the steps of installation.

Another object of the invention is the provision of a captive screw which may be incorporated in a fastening assembly without inadvertently becoming detached from said assembly.

Other objects and advantages of the present invention will be seen from the following specification and drawings wherein:

FIG. 1 is a perspective of the combination and strike box.

. FIG. 2 is a perspective of the strike plate and strike box shown attached to the jamb of a door.

FIG. 3 is an exploded view showing, in perspective, the bore on the jamb, the gripping element, the combination strike plate and box, and securing screw.

FIG. 4 is a rear elevation of the gripping element.

FIG. 5 is a side elevation of the gripping element showing the curvature thereof. I

FIG. 6 is a horizontal cross section through the bore strike plate in the jamb showing the combination strike plate and box and securing means assembled.

3,251,619 Patented May 17, 1966 FIG. 7 is an enlarged cross section through the bottom of the strike box showing the screw in relation to said bottom in its normal position after the thread of the screw has mutilated the plate so as to prevent axial movement of the screw relative to the plate.

FIG. 8 is a rear elevation of a modified form of gripping element showing the surrounding structure in dotdash lines. I

FIG. 9 is a side elevation of the gripping element of FIG. 8.

In detail, and first with reference to FIG. 2, the invention is adapted to be employed on a door jamb 1 provided with a door stop 2. It will 'be understood that the door (not shown) swings from a doorjamb opposite jamb 1 and one face of the door fits, in its closed position, against the face 3 of the stop 2 With the opposite face of the door usually substantially coplanar with the face 4 of the jamb 1.

By the present invention a strike plate 10 is applied to the face 11 of the jamb and said strike plate has integrally connected thereto a strike box 9 having upper and lower walls 12, 13, an outer wall 14 substantially perpendicular to face 11 of jamb 1, and an inner slantingly disposed wall 15. It will be apparent that the outline of the line of intersection of the strike plate with the walls of the strike box is generally D-shaped so as to correspond with the conventional cross sectional contour of the latchbolt (not shown) of the lockset. Said latchbolt, when projected into the strike box as the door is closed, is provided with a fiat face which lies alongside the sidewall 14 of the strike box (FIG. 6).

The strike plate 10 is shown as surface mounted in FIG. 2; that is, the strike plate is secured against the face 11 of the jamb 1. However, if desired, a mortise may be formed in the face of the jamb so as to sink the strike plate into .the jamb and make the outer surface of the strike plate coplanar with the face 11 of the jamb. In such a case, a generally trapezoidal shaped mortise is formed so as to register with the converging upper and lower edges 20, 21 of the strike plate and the inner vertical edge 22. The outer portion of the strike plate terminates in the usual curved cam portion 23 which serves to depress the latchbolt as the door moves toward closed position.

At this point it will be noted that when the strike plate is used with a mortised jamb the novel trapezoidal shape 'shown enhances the resistance of the strike plate to being shifted relative to the jamb when the door is slammed. This is because the material of the jamb adjacent edges 20, 21 offers additional resistance to such failure as compared, for example, to parallel edges which would con tribute no additional resistance. It should be understood in this connection that the force tending to cause failure is the force of rebound of the door from the stop 2 and .not the closing force of the door itself. When the strike plate is surface mounted the strengthening effect of the trapezoidal shape is also present, although to a lesser degree, because the strike plate is very tightly abutted against the face 11 of the jamb thereby slightly compressing said face.

An advantage over circular strikes is also present in the trapezoidal shape of the instant strike plate in that the vertically disposed edge 22 may be made very close to the latch opening thereby giving greater clearance between said edge 22 and the adjacent door stop 2.- With a circular strike plate in which the outer periphery of the plate is made concentric with the bore in the jamb, interference frequently exists between the edge of the plate and the door stop, particularly in the case of thin doors and narrow jambs.

By the present invention substantial savings in the cost of mounting'the strike plate structure are effected, first,

.3 by surface mounting the strike plate, and, second, by securing the strike plate and strike b'ox combination in a cylindrical hole in the jamb which may be bored in a matter of seconds.

If it is desired to sink the trapezoidal shaped strike plate in a mortise it will be noted that only three straight cuts need be made to do so. This feature is particularly important if it is found desirable to form such a mortise after the cavity for the strike box has been formed. In the case of a circular strike it is virtually impossible to form a circular mortise Without a boring tool of some kind and the strike box cavity eliminates the center for the use of such a tool.

As best seen in FIG. 6 a bore is formed in jamb 1 opening outwardly of face 11 and in coaxial alignment with the latchbolt (not shown) when the door is closed. Bore 3% is of a size to accommodate the strike box 9, and upper and lower walls 12, 13 of said strike box may be curved so as to be snugly received adjacent the inner sidewalls of said bore.

Strike box 9 is provided witha bottom wall 31 in which a circular hole 32 is formed to receive therethrough a screw 33. Hole 32 is positioned in bottom 31 so as to be coaxial with the centerline of bore 30 and, of course, the line of action of the latchbolt. Only one screw 33 is re lied on to secure the strike plate structure in place because it is desirable, at installation, to be able to swing the combined strike plate and box about the axis of screw 33 so as to adjustably set the same in a position with the flat side 14 of box 9 parallel to the flat face of the latchbolt in the event the latchbolt is installed with its fiat face in a tilted position relative to its proper vertical setting. Such permitted rotation is also useful in taking up play between the latchbolt and strike, thereby eliminating door rattle.

If the strike plate is installed before the door jamb is secured in place, it is, of course, a simple matter to provide an anchor plate or some other device on the opposite side of jamb 1 from face 11 so as to receive a machine screw or the like fastening element therethrough to tighten the strike plate and box in the position of FIG. 6. The present invention, however, provides means for fixedly securing the strike plate and box in place after, as well as before, the jamb is installed and when access to the inner side of the jamb is prevented.

The means for receiving the inner end of screw 33 is a gripping plate or anchor generally designated 36 (FIGS. 3-6). As best seen in PEG. 4 the anchor, or gripping plate 36 is preferably formed from a section of sheet material in the order of .015 inch thick and comprises a central portion 37 (FIG. 4) which is apertured as at 38 to receive screw 33 therethrough. In order to facilitate reception of the screw 33 a substantially semicircular portion 4% is partially struck out from the plate to form a partial helix complementary to the helix of the screw.

As best seen in FIG. 5, the gripping plate is dished to a generally spherical shape so as to enhance the resistance of the plate to diaphragming, and the helix receiving portion 40 is formed on the convex side. It will be seen that the dished shape of the gripping plate facilitates insertion of the same in the bore 3%.

Extending outwardly from the central portion 37 of the plate 36 are a plurality of legs 42. Three legs are shown in FIG. 4 so as to form a triskelion shape, but it will be apparent that a greater number of legs maybe formed. Although the device may operate in the desired manner with two such legs, it is preferable that three or more legs be employed to obtain an even distribution of loading.

In forming the gripping element 36 each leg 42 is defined by cutting the plate to provide an edge 43 on each leg and an adjacent edge 44- on the central portion of the plate. At the end of each such cut the plate is provided with a small circular aperture 45 which not only reduces the stress concentration but also facilitates deflecting the legs with a permupept set toward the center of the plate as shown in FIG. 4 to provide an overlapping portion 46.

The gripper plate is heat treated after being formed as above described so that a strong resilient anchor is provided.

The parts of FIG. 3 are assembled by threading screw 33 through hole 32 in the bottom 31 of the strike box until the head of the screw is against said bottom. The gripper element 36 is then threaded onto the end of the screw for a few threads to about the position shown in FIG. 6. At installation the entire assembly may be pressed into bore 30 with the convex side of gripper element 36 leading until the inner side of strike plate 10 abuts face 11 of jamb 1. During this step the legs 42 of the gripper element deflect toward the open end of the bore 36 so that the sharp outer ends 47 of said legs prevent the reverse movement of the gripper plate.

The strike plate it may then be tightened against the face 11 of jamb 1 simply by rotating screw 33 with a screw driver. It will be noted that any tendency that the gripper plate 36 may have to rotate with the screw is eliminated by the fact that the sharp ends 47 of the legs 42 dig into the sidewalls of the bore. The direction in which the legs 42 are disposed is, of course, made the same as the direction of rotation of the screw 33 when the latter is tightened.

Before the screw 33 is tightened, it is apparent that the step of pressing the gripper element 36 into the bore 30 will have resulted in the central body portion 37 of the gripper element being spaced slightly inwardly from the adjacent legs. Thus, as screw 33 is tightened the central portion 37 of the gripper element is pulled outwardly toward the open end of the bore 30 against the inherent resistance of the material of the plate. However, substantially increased resistance to outward movement of the plate is encountered when the central portion abuts the legs 42 along the overlapping portions 46. By this structure, failure of the gripper plate or screw cannot take place without the application of an inordinate amount of torque on screw 33. The result is that strike plate 10 may be pulled against face 11 of jamb 1 with an extremely high pressure so that there is no tendency for the strike plate to shift even under rough usage.

An important feature of the invention resides in the fact that the strike plate may readily be removed and another substituted if this becomes desirable. For such replacement it is merely necessary to unscrew screw 33, and remove the strike and gripper plate 36 if necessary. The procedure hereinabove described may then be followed for installation of the new strike plate and box.

Another important feature of the invention resides in the fact that the strike, the gripper element and the screw may be packaged in an assembled condition as shown in FIG. 6 so that it is merely necessary for the carpenter to remove the assembly from its package and apply it to the bore. To obviate the possibility of the screw 33 becoming loose it is assembled with the bottom of the strike box as shown in FIG. 7. As an example, the screw 33 may be /8 long, 18 threads per inch, with the major diameter of the threads about .138" and a thread pitch of By employing a plate about .035" thick to form the bottom 31 and drilling hole 32 to a diameter of .110" the screw 33 may be threaded into hole 32 until the head of the screw abuts the bottom. By continuing to turn screw 33 after the head of the screw engages the outer side of the bottom 31, the inner side of the bottom is mutilated by the adjacent end of the thread to the shape shown in FIG. 7. Such mutilation takes place because the screw is hardened steel and the strike plate and box is made of much softer material, preferably brass.

The additional turns of the screw after the same has been completely threaded through hole 32 causes the sharp end of the screw to cut a chip from the adjacent circular edge of the hole and, at the same time, to upset the adjacent material until a frustoconical portion 48 is formed.

This formation prevents the thread of the screw from biting into the material of the bottom 31 when the direction of rotation of the screw is reversed if it is attempted to unscrew the screw from the bottom. By this construction there is no likelihood of the screw becoming detached from the strike or being pushed outwardly of the hole 32 by the reaction of the gripper during installation.

At assembly, and prior to packaging, it is merely necessary to thread the gripper element 36 onto the end of screw 33 for a few turns of the latter before packaging the same.

A modified form of gripper element generally designated 50 is shown in FIGS. 8, 9. Use of a gripper element of this type is advisable in some instances if the thickness of the wood between the bore and the outer face 4 of the jamb is so small that one of the legs 42 of gripper element might penetrate the thin wall 60.

The device of FIGS. 8, 9 is designed to insure that a sharp point of the gripper will never register with the thinnest section of the wood 60 between bore 30 and the outer face 4 of the jamb.

The gripper element comprises a central section 51 from which extends a pair of relatively narrow legs 52, 53 which are angularly offset at an angle of about 100". Another pair of generally parallel legs 54, 55 extend generally horizontal from the central portion 51.

A positioning flange 57, centrally between legs 52, 53 is bent at right angles to the central portion 51 so that it engages the flat sidewall 14 of the strike box 9 when the gripper element is secured to the screw 33 (not shown in FIG. 9). In all other respects the element 50 is similar to the above described element 36, having a central aperture 58 for receiving the screw 33 therethrough, and an upset partially annular portion 59 surrounding said aperture.

It will be apparent from FIGS. 8, 9 that when gripper element 50 is secured by screw 33 to the combination strike and strike box, flange 57, although permitting relative axial movement between the gripper element and the strike box, limits relative rotation. Thus the legs 52, 53 remain at all times in a position angularly offset from the narrow section 60 of the door jamb and there is nochance of any one of the legs registering with said narrow section. I

The above very specific description of preferred forms of the invention should not be taken as restrictive of the invention as it will be apparent that various modifications in design may be resorted to without departing from the following claims.

I claim:

1. A strike structure comprising:

a strike plate adapted to be received on an inner face of a door jamb,

a strike box integral with said strike plate and adapted to be received in a cylindrical bore formed in said jamb and opening outwardly of said face,

said strike box having a bottom provided with an aperture located to be coaxial with said bore when said box is received in the latter,

a screw passing through said aperture from inside said box and having a head adapted to engage said bottom, and

means inwardly of said bottom for receiving said screw,

whereby said strike plate may be swung on said screw about the axis of said bore for adjustably positioning said strike bolt relative to the cooperating latchbolt.

2. Strike construction comprising:

a strike plate adapted to be received on the face of a door jamb,

a strike box integral with said strike plate and adapted to be received in a cylindrical bore formed in said jamb and opening outwardly of said face,

said strike box having a bottom provided with an aperture located to be coaxial with said bore when said box is received in the latter,

a screw passing through said aperture from inside said box and having a head adapted to engage said bottom, and

a gripper element adapted to be positioned transversely of said bore in gripping engagement with the sidewalls thereof and receiving said screw therethrough,

whereby said strike plate may be tightened against said face by rotating said screw and may be swung about said screw for adjustably positioning said strike plate relative to the cooperating latchbolt.

3. A construction according to claim 1 wherein said screw is rotatably supportedon said bottom and fixed against axial movement relative to said bottom.

4. In combination with a strike that includes an integral st-rike box formed with a flat sidewall adapted to engage the flat side of a cooperating latchbolt,

a gripping element adapted to be positioned within a bore in which said box is received,

said gripping element being provided with a plurality of legs adapted to engage the sidewalls of said bore at their outer ends, and

a tab formed on said element and adapted to engage said flat sidewall of said strike box for holding said element in a predetermined angular relation relative to said strike box.

5. In combination with a door jamb provided with a cylindrical bore opening outwardly of an inner face of said jamb,

a strike plate on said inner face,

said plate being provided with an integral strike box received in said bore,

said box having a bottom provided with an aperture coaxial with said bore,

a screw passing through said aperture from inside said box and having a head in engagement with said bottom,

means inwardly of said bottom for receiving said screw,

whereby said strike plate may be swung on said screw about the axis of said bore for adjustably positioning said strike plate relative to the cooperating latchbolt.

References Cited by the Examiner UNITED STATES PATENTS 1,903,782 4/1933 Eyring 292-340 X 2,272,241 2/1942 Pendring 292-340 2,503,536 4/1950 Yeakel 292-341.18 2,654,620 10/1953- Tinnerman 15141.73 X 2,818,901 1/1958 Becker et al. 1514l.73 2,861,617 11/1958 Tinnerman 15l-41.73 2,964,346 12/1960 Check 292-340 2,982,989 5/1961 I-Ieyer 15141.73 X 2,987,811 6/1961 Acres 151--69 X 3,079,493 2/ 1963 Goldstein 151--41.73 X 3,152,825 10/1964 Schlage 292-340 FOREIGN PATENTS 664,218 1/1952 Great Britain.

PATRICK A. CLIFFORD, Primary Examiner. M. HENSON WOOD, 112., Examiner.

LEITN R. E, MOORE Assistant Examiners. 

1. A STRIKE STRUCTURE COMPRISING: A STRIKE PLATE ADAPTED TO BE RECEIVED ON AN INNER FACE OF A DOOR JAMB, A STRIKE BOX INTEGRAL WITH SAID STRIKE PLATE AND ADAPTED TO BE RECEIVED IN A CYLINDRICAL BORE FORMED IN SAID JAMB AND OPENING OUTWARDLY OF SAID FACE, SAID STRIKE BOX HAVING A BOTTOM PROVIDED WITH AN APERTURE LOCATED TO BE COAXIAL WITH SAID BORE WHEN SAID BOX IS RECEIVED IN THE LATTER, A SCFEW PASSING THROUGH SAID APERTURE FROM INSIDE SAID BOX AND HAVING A HEAD ADAPTED TO ENGAGE SAID BOTTOM, AND MEANS INWARDLY OF SAID BOTTOM FOR RECEIVING SAID SCREW, WHEREBY SAID STRIKE PLATE MAY BE SWUNG ON SAID SCREW ABOUT THE AXIS OF SAID BORE FOR ADJUSTABLY POSITITONING SAID STRIKE BOLT RELATIVE TO THE COOPERATING LATCHBOLT. 